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Comments on: ``Weinberg's Nonlinear Quantum Mechanics and Einstein-Podolsky-Rosen paradox'', by Joseph Polchinski

Bogdan Mielnik
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Abstract

Contrary to the opinion of J. Polchinski [Phys.Rev.Lett. {\bf 66}, 397-400 (1991)], the phenomenon of superluminal messages in nonlinear versions of quantum mechanics is not a specific difficulty in a class of theories formulated by S. Weinberg [Ann.Phys. (N.Y.), {\bf 194}, 336-386 (1989)]. It appears in all schemes which try to enlarge the orthodox class of observables, while conserving the traditional structure of the pure and mixed states.

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Bogdan Mielnik. 2001-01-03. Comments on: ``Weinberg's Nonlinear Quantum Mechanics and Einstein-Podolsky-Rosen paradox'', by Joseph Polchinski. https://arxiv.org/abs/quant-ph/0012041

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